Rebound absorber for vehicles



Dec. 14, 1926.

J. A. KNIGHT REBOUND ABSORBER FOR VEHICLES Filed Dec. 11. 1919 I N VEN TDR.

Patented lDec.'v 14, .1926.

{PATENTj OFFICE.

JOHNA'. RNIGIIT, OE IIAMILTONQONTARIo, CANADA. AssIGNon :rol ,JOHN WARREN 'I WATSON COMPANY, OF BHILADELPH PENNSYLVANIA.

Application led Dcember'll, 1919. Serial No. 344,201.

lIt is well known that much discomfort is caused to the occupants of an automobile or i -other vehicle in which the body is spring suspended, and sometimes damage to the car,

sby the acquired momentum orrebound of the b dy after the sprin s have been compressed the passage of t in the road. v

l Many devices 'have been put on the market to absorb-this rebound, which are common-v ly known as rebound snubbers or shock absorbers, but most of them possess objectionable features depending on their type. Some shock absorbers have the effect of increasing. the resiliency ofthe-spring support, thus eliminating a eat deal 'of the discomfort caused by sma road inequalities, but failing to check the rebound caused by a large inequality. Such shock absorbers are of ma terial benefit only in cases where the spring suspension of the automobile to which they ire applied has not; been designedto have suvflicient resiliency.'

Other shock absorbers check the reboundV from a large inequality yvery effectively, but

also check with practically' the same -or greater resistance the rebound from a small Inequality, thus causing discomfort from smallinequali'ties which the ordinary spring suspension, without the shock absorber, would render almost negligible. Still other shock absorbers check the rebound with a resistance proportioned to the acquired momentum of the bod with respecttothe axle. Such shock absor ers are slow in acting as the momentum lmust be acquired before they come into operation. --Others of the t pe dependent O11 the displacement of a uidthough free of some of the above ob- -jections, are expensive and liable to wear and get out of order.

Myobject therefore is to devise a shockabsorber, or vreboundabsorber asV I prefer to term it, which will be free from the above set forth defects, and in which the rebound checking resistance is easily adjusted. I at` tain my object by so constructing the ablsorber 'that the rebound is checked by a frictionalresistance the major portion of which is substantially proportional to the force tending to produce the rebound which resistance takes immediate effect atv the time rebound commences, or, otherwise stated, in my rebound absorber the major portion of e car over inequalities the frictional resistance opposing separation ofthe bod and axle of the vehicle increases substantia 1" in proportion to the extent of the approach of the axle to the body from a positionof zero compression of the springs connecting the body and axle.

The advantage of a rebound absorbing resistance, the major port-ion of which is sub stantially proportioned to vehicle spring compression, such as is obtainedv with my construction, is apparent from the service Allroad vwhich it is required'to render. inequalities are of two classes, rises and depressions in the road surface. The purpose of the vehicle spring is to permitv the body to move with a smooth motion, while the Wheels vibrate up and down overthese inequalities. The body instead of receiving the hard, vsudden blows delivered to the wheels, receives blows ydelivered by the compressed springs. Such blows when resulting from the rough road conditions are of suflicient value Ato cause the body to rebound violently -if .the spring action is not con# '"trolled.

A resistance opposing separation of the body and axle of the vehicle, the major portion of which is not pro ortioned to .vehicle spring compression7 ten I to oppose too severely the `dropping ofv the wheels into aroad depression under decreased spring compression, and to hold the springs in compression, causing them through their decreased cushioning powerA to transmit to the body a severe blow, when the-wheels strike4 the op posite side of the depression. Such resistance tends also to insuficiently oppose the rebound action from increased spring ccmpression, dueto a severe rise inthe road..

Any adjustment of such resistance to eiiiciently l`control sprin action, dueA to `one class of road inequality, makes,- it lessef- {icient to control spring action due to thev enables it to perform f this function, and

'-whichvI claim as constituting novelty in con# struction and arrangement o1: parts, and

similar devices.

The invention 1s heremafter more fully described and illustrated in'the accompanying drawings in which Fig. 1 is aside elevation, with one side disk removed, of my improved rebound ab sorber;

Fig. 2 a cross section of the same; and

Fig. 3 a side elevation, partly broken away, of a slight modification of the invention, one side disk being removed.

In the drawings like numerals of lrefer ence indicate corresponding parts in the different figures.

1 is a snubber part adapted to be connected to one of two parts of a vehicle, either the body "or, some-part rigidly connected wit-h the body, or the axle .or some part rigidly connected with the axle.,Y Y2 is thesecond snubber part also adapted tobe yconnected to the body or axle of the vehicle..

In practice I- prefer to connecttheA snubber part 1`with Athe body of the vehicle and the snubber' part 2 to-the axle ofthe vehicle, or

parts rigidly connected therewith. It willv be understood, of course,that the device is applicablefor use in absorbing the'rebound of any two spring connectedv parts subject to shock causin departure from the normal lrelative position of the two parts and the terms axle and body used in the claims are to be taken as including any such parts.

The two snubber parts are relatively movable in correspondence with changes in the relative vertical position of the vehicle body and axle, and the arts' are rovided with braking surfaces a apted to e overlapped in accordance with therelative, position of the body and axle. The' device is also so arranged that` friction creating contact `of one part against the yother is increasedm some proportion to the extent of approach of the axle to the body.

- The part 1 is mounted on a stu-d 3 which extends from a plate 4 bymeans of which it may be secured to the body of thevehicle. In the preferred construction the part 1 is formed with .a hub 5 keyed on the stud 3. VThe-part 1 is a drum provided with acylindrical braking surface 6. The part 2 of the absorber is preferably formed of two disks journalled on the stud 3 and connected` by a' bolt 7.. .To this second part 2 is connected the strap 8, which is provided at one end with a loop 9 or othermeans, by means of which it may be connected with the axle of the vehicle. This strap passes round the cylindrical braking surface 6 of the part 1, which itis adapted to directly or indirectly engage. The strap `.8 thus forms the braking surface of the part 2 (sce Fig. 3) and also the means of connecting the part'2 with the axle ofthe vehicle.

In practice it is desirable that the strap ferred construction, this flexible brake band,

which is of any ordinary material employed forthat;` urpose, is secured to a resilient dividedmet-al band 11,` which is provided withaf'loop passing round the bolt 7. The strap 8 is also riveted to this metal band as shown at"12., A pull on thev strap -8.thus tends'to rotate they part 2 of the obsorber, in

-which motion the brake band '10 participates. The part- 2 ofthe'absorber is normally actedupon by a spring tending to rotate it in the direction indicated by arrow to cause the strap v8, which'is in effect part ofthe second snubber part *2, to wrap itself round a greater .arc ofpbr'aking vsurface 6 than thenormal, and in roportion to the approach. of the axleto tie body. It follows therefore that the circumference ,ofthe drum should be approximately equalto `the range of relative movement of the body and axle. .A coil spring 13 is provided to rotate the second snubber part, one end being-se cured to the snubber part -1 and the other end to the snubber part 2. As the braking. effect, to attain my object,'must depend on the overlapping of the stra-p on the drum as` largely as possible, this spring must be sufficiently long and flexible to give nearlyeven tension throughout its range of action. i

The mode of operation of the 'device is substantially as follows. lWit-h'the vehicle standing still, theposition of the parts'of -the absorber would be substantially as shown with a short section of the strap 8 overlapping the cylindrical surface 6 and consequently a similar short section of the brake band 10 pressed against said surface. When the vehicle is in motion and passes over an inequality in the road, the body and axle approach one another and the vehicle springs are further compressed. The strap S is thus slackened and the spring 13 rotates the member 2 in a counter-clockwise .direction and Winds a longer section of the strap 8 and brake band 10 on the cylindrical surface 6.y

As the pressure of -the vehicle springs overcomes the inertia of the body, thev latter moves awa from the axle.` ThisI upward motion of t e body produces a tension on tht able force .against the braking surface 6,.

causing a braking effect which opposes the clockwise rotation of the part 2 and puts an increased tension on the strap, which tension the body relative to the axle and absorbs the force of the rebound.

As the body moves upwards and the part 2 rotates in a clockwise direction, the overlap Aof the strap 8 and the length of the portion of the brake band 10 pressed against the surface 6 becomes shorter andthe braking effect less, thus permittin 'of freer relative movement of the body an axle. It will be seen therefore that the braking effect which opposes rebound increases' as the body and axle approach and decreases as theyfseparate and therefore the absorbing effect is proportionate to the force of the road shocks to which the car is subjected'tending to cause` rebound. A

In practice the arc of overlap of the strap on the cylinder braking surface 6 will vary from approximately 0 to 300 or to p ut it otherwise, the circumference of the drum is substantially equal to the possible relative overlap of the strap on thedrum.

The principle of'operation hereinbefore set forth may beembodied in constructions differing materially in detail from 'that hereindescribed and shown.

What I claim as my invention is 1. In mechanism adapted for use in con nection with, two relatively movable elements for checking their relative motion in one direction, a drum adapted to be secured to one of said elements, a friction shoe, in the form of, an incomplete or split ring, slidably positioned around said drum, a spring operatively connected to said shoe for advancing one end thereof around said drum, a fourth member secured to said shoe and extending beyond its Said., advanced end, and a flexible member secured to said extended portion of said fourth member. and adapted l to be connectedto said other element.

.2. In mechanism adapted for use in conl nection with two relatively movable elements-` for checking their relative motion in. one direction, a drum adapted to be secured to one of said elements, a friction shoe, in the form of an incomplete or split ring, slidably positioned around said drum, a spring operatively connected to said shoe for advancing one end thereof around said drum, a fourth :member secured to said shoe and extending beyond its said advanced end, a iexible member secured to said extended portion of said fourth member and adaptedl to be connecte to said other element, said fourth member lying between said friction shoe and said iiexible membert I i 3. In mechanism adapted-for use 1n connection with two relatively movable elements for checking their relative motion in oney direction, a drum adapted to be secured to Aone of said elements a flexible member adapted; to be secured .to the other ofsaid elements, a spring connecting said drum and said' rum and theend of the inner'convolution of said spring being held in fixed relatio with one end of said flexible member..

4. In mechanism-adapted for use in con'- nection vwith two relatively movable -elements for checking, their relative motion in one direction, a drum adapted to be secured to one of said elements, a'. iiexible member adapted to be secured to the other of said elements, a spring connected at its outer end to said drum and at its inner end to means for transmitting the power of said spring to said flexible member to increasingly overlay the flexible member around the drum, and a bearingfor said means, said bearing lying within-the inner convolution of said spring. l

5. In mechanism adapted for use in connection with-two relatively movable elements 'for checking their' relative motion in one ativelyconnected to said shoe for advancing one end thereof aroundsaid drum, a fourthmember secured to said shoe and extending beyond its said advanced end, a fiexiblel member secured to said extended portion of said fourth `member and adapted to be connected to said other element, said fourth member substantially surrounding said friction shoe and lying between said frictionr shoe and said fiexible member.

. 6. In mechanism adapted foruse in connection with two relatively movable elements ico for checking their relative motion in one direction, a drum .adapted 'tobev'secured to one of said'elements, a frictionl member 1n contact with sai'ddrum, a spring operativellyconnected t0 said friction member for a( vancing one end thereof .aroufndnsa-id.,drum',`

a fourth member secured. to, lsaid friction' member' and extending beyond its said advanced end, and a flexible member secure'dto said extended portion of said fourth member and adapted to be connected to said other vancing' one en-d thereof around said drum, a,-

fourth member securedlto said' friction member and extending beyond its said advanced end,'a`nd a -fiexible member secured to said les lil

extended portion of said fourth member and adapted to be connected to said other element, said4 fourth member lying between aid friction member and said flexible mem- 8.. In lmechanism adapted for use in conf tioned member having a portion extending vaway from Contact` with said frictionv mem- 1 nection with two relatively movable elements for checking' their relative motion in one direction, a drum adaptedto 'be secured to one of said elements, a friction member in contact with said drum, a spring operativel connected to said friction member for ac-L vancing a part thereof around said druma 'fourth member secured to said friction mem'` ber and extending beyond the said advanced part, and a flexible member secured to. said extended portion of said fourth member and ment.

adapted to be connected to saidother elen ection with two relatively movable elements 9.'. In mechanism adapted for use in connection with two relatively movable elements for checking their relative'motion 1n one .di-

rection, a drum adaptedto'be secured to oneof said elements, a friction member in con-4 tact with said drum, a spring operatively connected to said friction member 'for ad- .Vancing a part thereof around said drum, a fourth member secured to said'friction member and extendingbeyond the said advanced part, and a flexible member secured to said` extended portion of said fourth member and nection with tworelatively movable elementsv rection, a.

adapted to be connected to' said other ele-V ;ment, said fourth member lying between said v friction member and 'said flexible member.

l0. In mechanism adapted for use in confor checkin their relative motion in one dicured to one of saidelements, a second member revolvable about. said drum member,

a spring operatively connect-ing said drum .member between said drum member and said second mentioned member, said second mentioned member having a portion extend-- for checking their relative motio'nin one direction, a drum member adapted to be serum member 'adaptedf'to be se;`

-'.vember .1919. cured to one of said elements, asecond member revolvable about said drum member, a

spring operatively. connecting .said drumv member and said second mentioned member for relatively revolving them,- a friction member between said drum member and said second mentioned member, said second menlsaid other element, the parts being so formed and associated as to causea decrease 'in the yforce required to relatively revolve said drum member and saidv second mentioned member as they.`are"relativelv revolved by Said lexible member.'

' 12. In mechanism adapted for use inconfor checking their relative motion in one direction, a `drum member adapted to be se;l

spring `operatively `connectin member and said second mentioned member for relatively revolving them, said second mentioned member having a portion adapted to transmit pressure directlyy down against said drum member and having a portion not so adapted, and a flexible member secured to said non-adapted portion. of said second menf tioned member and adapted -to .be secured to said`other element..

13. In mechanism adapted foi' use in connection .with two relatively movable elements for checking their relative motion in one direction, a drum member adapted to be se` cured to one of said elements, aisecond memberrevolvable .about .said drum member, a spring operativelyv connectin said drum memberand said second mentioned member for'relatively revolving them, a iexible mem-H ber secured to said second mentioned memberand adapted tobe secured to saidother element, said second mentioned member having a portion adapted to ktransmit pressure from said iexible -member directly down against said drum member 'and having a portion not so adapted, said flexible membber being secured to said second mentioned mem` ber at said portion of sai-d secondmentioned member which is not adapted for transmit- .ting pressure as above mentioned@ Signed at Toronto this 25th day of No JQHN A. KNIGHT. 

